Browsing by Keywords "Phase transitions"
Now showing items 1-17 of 17
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Effect of the superconductivity transition on the response of YBCO edge transition bolometers
(2003)Dependence of the phase and magnitude of the response of Y-Ba-Cu-O edge transition bolometers on the superconducting transition is studied. The responses of both large and small area devices were investigated and several ... -
Effective electron-electron interactions and magnetic phase transition in a two-dimensional electron liquid
(Elsevier B.V., 2007)We investigate the spin-dependent effective electron-electron interactions in a uniform system of two-dimensional electrons to understand the spontaneous magnetization expected to occur at very low density. For this purpose, ... -
Effects of milling and annealing on formation and structural characterization of nanocrystalline intermetallic compounds from Ni-Ti elemental powders
(2012)Nickel and Titanium elemental powders with a nominal composition Ni-50 at.%Ti were mechanical alloyed in a planetary high-energy ball mill in different milling conditions (5, 10, 20, 40 and 60 h). The investigation revealed ... -
Electronic structure, insulator-metal transition and superconductivity in K-ET2X salts
(1998)The electronic structure and superconductivity of layered organic materials based on the bis(ethylenedithio)tetrathiafulvalene molecule (BEDT-TTF, hereafter ET) with essential intra-ET correlations of electrons are analysed. ... -
Existence of a metallic phase in a 1D Holstein-Hubbard model at half filling
(Elsevier B.V., 2007)The one-dimensional half-filled Holstein-Hubbard model is studied using a series of canonical transformations including phonon coherence effect that partly depends on the electron density and is partly independent and also ... -
Free expansion of two-dimensional condensates with a vortex
(Institute of Physics Publishing, 2003)We study the free expansion of a pancake-shaped Bose-condensed gas, which is initially trapped under harmonic confinement and containing a vortex at its centre. In the case of a radial expansion holding the axial confinement ... -
Freezing transition of the vortex liquid in a layered superconductor
(Elsevier Science Publishers B.V., 2001)The self-consistent theory of Singwi, Tosi, Land, and Sjolander is used to describe the liquid-solid phase in a layered superconductor in the limit of weak interplane correlation effects as would be applicable to BSCCO ... -
Low-temperature phase transitions in TlGaS2 layer crystals
(Pergamon Press, 1993)Polarized Raman scattering spectra of TlGaS2 layer crystals have been studied for the first time as a function of temperature between 8.5 and 295 K. No evidence for a soft mode behaviour has been found. The anomalies ... -
Low-temperature photoluminescence spectra of TlInxGa1-xS2 layer mixed crystals
(Pergamon Press, 1995)Low-temperature photoluminescence spectra of TlInS2, TlIn0.95Ga0.05S2 and TlIn0.8Ga0.2S2 layer crystals were studied in the temperature range 14-220 K. The temperature dependencies of bands 2.374 eV (A), 2.570 eV (E) and ... -
Pairing and vortex lattices for interacting fermions in optical lattices with a large magnetic field
(The American Physical Society, 2010)We study the structure of a pairing order parameter for spin-1/2 fermions with attractive interactions in a square lattice under a uniform magnetic field. Because the magnetic translation symmetry gives a unique degeneracy ... -
Phase transformation during mechano-synthesis of nanocrystalline/amorphous Fe–32Mn–6Si alloys
(Elsevier, 2013)Mechano-synthesis of Fe-32Mn-6Si alloy by mechanical alloying of the elemental powder mixtures was evaluated by running the ball milling process under an inert argon gas atmosphere. In order to characterize the as-milled ... -
Phonon squeezing in superconducting borocarbides
(Elsevier BV * North-Holland, 1994)The recently discovered superconductor LuNi2B2C is investigated in the context of strong electron-electron correlations modulated by a squeezed phonon mode propagating in the perpendicular direction to the layers with ... -
Radiative donor-acceptor pair recombination in TlInS2 single crystals
(Institute of Physics Publishing, 1999)Photoluminescence (PL) spectra of TlInS2 layered single crystals were investigated in the 500-860 nm wavelength region and in the 11.5-100 K temperature range. We observed two PL bands centred at 515 nm (2.41 eV, A band) ... -
Solid or liquid? Solidification of a nanoconfined liquid under nonequilibrium conditions
(American Chemical Society, 2006)There has been a long-standing debate about the physical state and possible phase transformations of confined liquids. In this report, we show that a model-confined liquid can behave both as a Newtonian liquid with very ... -
Temperature dependence of the phase of the response of YBCO edge-transition bolometers: effects of superconductivity transition and thermal parameters
(Institute of Physics Publishing, 2003)The variation of the phase of the response of YBCO edge-transition bolometers on crystalline MgO substrate is found to be dependent on the normal-superconducting transition. The phase of the response for T < Tc increased ... -
Tkachenko modes and structural phase transitions of the vortex lattice of a two-component Bose-Einstein condensate
(American Physical Society, 2006)We consider a rapidly rotating two-component Bose-Einstein condensate (BEC) containing a vortex lattice. We calculate the dispersion relation for small oscillations of vortex positions (Tkachenko modes) in the mean-field ... -
Trapped interacting Bose gas in nonextensive statistical mechanics
(The American Physical Society, 2002)We study the Bose-Einstein condensation (BEC) phenomenon in an interacting trapped Bose gas using the semiclassical two-fluid model and nonextensive statistical mechanics. The effects of nonextensivity characterized by a ...
